Suppose we were to translate the English sentence into Attic Greek or Latin.
Do not fight your brother, lest you, who are smaller than him, be hurt.
You can see how the relative clause, "who are smaller than him", is nested inside a purpose clause. That purpose clause begins with the conjunction lest, and we know that the passive verb "be hurt" should be in the subjunctive.
But what mood should the verb of the relative clause be? I am tempted to say it should take the indicative mood, as it's indicating a simple fact. Is this correct? Furthermore, would the answer be the same in both Greek and Latin?
Here are my Greek and Latin translations. One style point I'm a little unsure about is whether the verb of the relative clause should be placed at the beginning or end of its clause.
Noli pugnare tuο fratri ne tu qui es parvior quam is noceris.
μὴ μάχου τῷ ἀδελφῷ σου ἵνα μὴ σὺ ὅς εἶ μικρότερος ἢ αὐτὸς βλάπτῃ.