Yosef Karo, Shulchan Aruch — Yoreh Deah 385
“ A mourner is forbidden to engage in greetings. How does this work? For the first three days he does not greet anyone and if others do not know that he is mourning and greet him, he should not respond to them. ”
Yosef Karo, Shulchan Aruch — Yoreh Deah 385
“ One who finds his fellow a mourner in the first 30 days, he should comfort him but should not greet him. After 30 days he can greet him, but should not comfort him in the usual manner, rather in an subtle way, namely, that he should not mention to him the name of the deceased, rather he should say to him, “be comforted.” ”
