Matthew 5:6 (ESV):
6 “Blessed are those who hunger and thirst for righteousness, for they shall be satisfied.
When will this happen?
The Beatitudes begin with Matthew 5:
3“Blessed are the poor in spirit,
for theirs is the kingdom of heaven.
Around the middle, we have:
6 Blessed are those who hunger and thirst for righteousness,
for they will be filled.
will be filled.
χορτασθήσονται (chortasthēsontai)
Verb - Future Indicative Passive - 3rd Person Plural
This is one place where we can appreciate that the NT was written in Greek. It is not just a future tense but a future indicative. They will be filled not occasionally but repeatedly and routinely.
The Beatitudes continues to
10 Blessed are those who are persecuted because of righteousness,
for theirs is the kingdom of heaven.
The kingdom of heaven begins when one believes. It begins presently.
The Beatitudes end with
11“Blessed are you when people insult you, persecute you and falsely say all kinds of evil against you because of me. 12 Rejoice and be glad,
Rejoice and be glad now and it does not stop here:
because great is your reward in heaven, for in the same way they persecuted the prophets who were before you.
When shall those who hunger and thirst for righteousness be satisfied? Matthew 5:6
They shall be satisfied as soon as they believe and the satisfaction continues to eternity. This is a spiritual satisfaction and not necessarily a physical one.
It is not specified, but one can tell that a) they are already smacking the satisfaction that they are fighting a noble fight in order not to "conform to this world" (Romans 12:2), but to live according to the eternal values already in this world, having become thus "salt" of this world through the "fire", i.e. grace of Holy Spirit (Mark 9:49);
and b) this kind of course of their lives, that noble fight against sins and against conformity to earthly values, which fight is directed to the acquisition of eternal values, to acquisition of Jesus, who sits in the right hand of the Father, through keeping of His commandments, will be eventually crowned by eternal satisfaction in the Kingdom of Heavens "where only righteousness dwells" 2 Peter 3:13.
Thus, they will be satisfied both here in this life as fighters of a noble fight and in eternity as victors in this noble fight in Christ.
According to the Pulpit commentary:
"When shall they be filled? As in the case of vers. 3, 4, now in part, fully hereafter."
This appears to be saying that Joel 2:12-19 would soon be fulfilled by the good shepherd:
[Joel 2:12-19 NASB20] (12) "Yet even now," declares the LORD, "Return to Me with all your heart, And with fasting, weeping, and mourning; (13) And tear your heart and not [merely] your garments." Now return to the LORD your God, For He is gracious and compassionate, Slow to anger, abounding in mercy And relenting of catastrophe. (14) Who knows, He might turn and relent, And leave a blessing behind Him, [Resulting in] a grain offering and a drink offering For the LORD your God. (15) Blow a trumpet in Zion, Consecrate a fast, proclaim a solemn assembly, (16) Gather the people, sanctify the congregation, Assemble the elders, Gather the children and the nursing infants. Have the groom come out of his room And the bride out of her bridal chamber. (17) Let the priests, the LORD'S ministers, Weep between the porch and the altar, And let them say, "Spare Your people, LORD, And do not make Your inheritance a disgrace, With the nations jeering at them. Why should [those] among the peoples say, 'Where is their God?'" (18) Then the LORD will be zealous for His land, And will have compassion for His people. (19) The LORD will answer and say to His people, "Behold, I am going to send you grain, new wine, and oil, And you will be satisfied [in full] with them; And I will never again make you a disgrace among the nations.
All of the Beatitudes derive from the OT and all refer to the destruction of the destruction of the temple, Jerusalem and the Jewish theocracy, and the establishment of resurrected Israel of God aka the Kingdom of God, and the life and times of the Messiah.
[Ezekiel 37:11-12 NLT] (11) Then he said to me, "Son of man, these bones represent the people of Israel. They are saying, 'We have become old, dry bones--all hope is gone. Our nation is finished.' (12) Therefore, prophesy to them and say, 'This is what the Sovereign LORD says: O my people, I will open your graves of exile and cause you to rise again. Then I will bring you back to the land of Israel.
No longer will they be starving under the then current polity:
[Matthew 21:41-45 NLT] (41) The religious leaders replied, "He will put the wicked men to a horrible death and lease the vineyard to others who will give him his share of the crop after each harvest." (42) Then Jesus asked them, "Didn't you ever read this in the Scriptures? 'The stone that the builders rejected has now become the cornerstone. This is the LORD's doing, and it is wonderful to see.' (43) I tell you, the Kingdom of God will be taken away from you and given to a nation that will produce the proper fruit. (44) Anyone who stumbles over that stone will be broken to pieces, and it will crush anyone it falls on." (45) When the leading priests and Pharisees heard this parable, they realized he was telling the story against them--they were the wicked farmers.
[Ezekiel 34:2-8 NLT] (2) "Son of man, prophesy against the shepherds, the leaders of Israel. Give them this message from the Sovereign LORD: What sorrow awaits you shepherds who feed yourselves instead of your flocks. Shouldn't shepherds feed their sheep? (3) You drink the milk, wear the wool, and butcher the best animals, but you let your flocks starve. (4) You have not taken care of the weak. You have not tended the sick or bound up the injured. You have not gone looking for those who have wandered away and are lost. Instead, you have ruled them with harshness and cruelty. (5) So my sheep have been scattered without a shepherd, and they are easy prey for any wild animal. (6) They have wandered through all the mountains and all the hills, across the face of the earth, yet no one has gone to search for them. (7) "Therefore, you shepherds, hear the word of the LORD: (8) As surely as I live, says the Sovereign LORD, you abandoned my flock and left them to be attacked by every wild animal. And though you were my shepherds, you didn't search for my sheep when they were lost. You took care of yourselves and left the sheep to starve.
Some answers have tried to apply this section of Matthew, the [so called] Beatitudes to all sorts of applications. But the actual answer is very simple. And, you get that answer from context. Context is ‘king’.
Jesus is preaching the Kingdom. The Kingdom of Heaven. Heaven on earth, exactly as the ‘Lords’ prayer asked. Just previous to this message we have ...
MAT 4: 17 From that time Jesus began to preach and to say, “Repent, for the kingdom of heaven is at hand.”
So the answer to your question “When will this happen?” is future. Future because the Jews rejected him as ‘King’. The kingdom needed them to accept Him.
MAT 5: 6 ”Blessed are those who hunger and thirst for righteousness, for they shall be satisfied.”
This is outlining ‘right living’. That’s how the Kingdom of Heaven will be ‘run’. That will be the expectation, the expectation of the King. It also is a ‘guide’ as to how believers should ‘live’ in the Kingdom of God.
Some believe this Kingdom of Heaven will yet be. Hence the ‘future’ aspect to your answer. This being during the Millennium reign of Christ. But this aspect depends on your theology.
When shall those who hunger and thirst for righteousness be satisfied? Matthew 5:6
Matthew 5:5-6 NASB
5 “Blessed are the gentle, for they will inherit the earth. 6 “Blessed are those who hunger and thirst for righteousness, for they will be satisfied.
In what sense do those that hunger and thirst for righteousness be satisfied. When Jesus holy brothers and sisters, partakers of a heavenly calling inherit the earth when they rule over it as kings and priests for a thousand years. (Heb.3:1, Rev. 20:6)
Hebrews 3:1NASB
3 Therefore, holy brothers and sisters, partakers of a heavenly calling, consider the Apostle and High Priest of our confession: Jesus.
Revelation 20:6 NASB
6 Blessed and holy is the one who has a part in the first resurrection; over these, the second death has no power, but they will be priests of God and of Christ and will reign with Him for a thousand years.
Their spiritual hunger and thirst for righteousness will be fully satisfied in the new world. (2 Pet. 3:13) When God has finally eliminated all wickedness, the happiness of righteous ones will never again be undermined by lawlessness and unrighteousness. (Ps 37:9-11,17)
Psalms 37:9-11,17 NKJV
9 For evildoers shall be [b]cut off; But those who wait on the Lord, They shall inherit the earth. 10 For yet a little while and the wicked shall be no more; Indeed, you will look carefully for his place, But it shall be no more. 11 But the meek shall inherit the earth, And shall delight themselves in the abundance of peace. 17 For the arms of the wicked shall be broken, But the Lord upholds the righteous.