Mandatory Annual Pilgrimages

Deuteronomy 16:16-17

"Three times a year all your men are to appear in the presence of ADONAI your God in the place which he will choose - at the festival of matzah, at the festival of Shavu'ot and at the festival of Sukkot. They are not to show up before ADONAI empty-handed,

but every man is to give what he can, in accordance with the blessing ADONAI your God has given you.