The MT 1 Samuel 2:31 reads:
הִנֵּה, יָמִים בָּאִים, וְגָדַעְתִּי אֶת-זְרֹעֲךָ, וְאֶת-זְרֹעַ בֵּית אָבִיךָ--מִהְיוֹת זָקֵן, בְּבֵיתֶךָ.
Behold, the days come, that I will cut off thine arm, and the arm of thy father's house, that there shall not be an old man in thy house.
Or as the NIV (who actually follows the MT reading in this case) has it:
The time is coming when I will cut short your strength and the strength of your priestly house, so that no one in it will reach old age,
The way the MT chooses to vowelize זרע is really odd, since the context strongly suggests that the word זרע here should be taken as זֶרַע = seed/children rather than זְרֹע = hand/strength. This is actually clearly spelled out in the following verse that none will reach old age and they will all die before reaching maturity thereby cutting the line of Eli short.
Indeed some translations ignore the MT and interpret the verse in the more natural way. The ISV for example renders the verse as follows:
The time is coming when I'll cut away at your family and your ancestor's family until there are no old men left in your family.
I also think it is most unnatural to translate the Hebrew term into hand or strength, as it is entirely unclear what cutting off the strength of the house of Eli would mean in this context anyway.
Can anyone explain why the MT chooses to translate this verse in the most unnatural way (instead of children)? What evidence is there in favor of the MT, and how can it be justified?