Hadith.940 - Mansur ibn Yunus Buzurj asked Imam Jafar ibn Muhammad Al-Sadiq عليه السلام about a person who strives to cry during the obligatory prayer until tears flow.
Imam عليه السلام replied: "It is a source of great joy, by Allah سبحانه وتعالى."
The Imam also said: "When this happens, remember me in that moment”.