Why does Mark 10:21 in the NKJV include take up your cross where other translations do not? [duplicate]

Question

In Mark 10:21 Jesus says

And Jesus, looking at him, loved him, and said to him, “You lack one thing: go, sell all that you have and give to the poor, and you will have treasure in heaven; and come, follow me.” - ESV

while the NKJV includes

Then Jesus, looking at him, loved him, and said to him, “One thing you lack: Go your way, sell whatever you have and give to the poor, and you will have treasure in heaven; and come, take up the cross, and follow Me.”

I've noticed this difference across many translations, NASB, NIV, HCSB, etc.

Why is there a difference in the NKJV? And what effect does it have on our understanding of Jesus' words?

Answer 1

I can't improve on Bruce Metzger below, but will explain it. He wrote that "take up the[your] cross" is only found in some of the more resent texts using the newer handwriting (minuscules). This phrase isn't present in the older manuscripts of the New Testament.

 10:21      δεῦρο ἀκολούθει μοι {A}

The Textus Receptus, following A and many minuscules, adds a gloss from 8:34, ἄρας τὸν σταυρόν. The shorter text is strongly supported by א B C D Δ Θ Ψ al.

Metzger, B. M., United Bible Societies. (1994). A textual commentary on the Greek New Testament, second edition a companion volume to the United Bible Societies’ Greek New Testament (4th rev. ed.) (p. 89). London; New York: United Bible Societies.