Adam Clarke on Leviticus 19:14

Thou shalt not curse the deaf - Or speak evil of him, because he cannot hear, and so cannot vindicate his own character.

Nor put a stumbling - block before the blind - He who is capable of doing this, must have a heart cased with cruelty. The spirit and design of these precepts are, that no man shall in any case take advantage of the ignorance, simplicity, or inexperience of his neighbor, but in all things do to his neighbor as he would, on a change of circumstances, that his neighbor should do to him.