The 277th prohibition is that a judge is forbidden from having pity on a poor person by favoring him unjustly in judgment. He must rather treat the rich and poor equally, and require them to pay whatever the judgment is.1
The source of this prohibition is G‑d's statement,2 "Do not favor [even] the poorest man in his lawsuit." This prohibition is repeated in the verse,3 "Do not give special consideration to the poor."
The Sifra4 says, "He should not say, 'He is poor, and since both I and the rich litigant are required to support him, I will rule in his favor, and he will be supported in an honorable way.' The Torah therefore says, 'Do not give special consideration to the poor.' "
