What is the ruling on intentionally weeping during prayer with the aim of increasing devotion (khushu') and softening the heart, and so that Allah may shade the worshipper with His shade and forbid him from the Fire, and does this invalidate the prayer?

If a person cries during their prayer out of overwhelming awe of Almighty Allah, their prayer is not invalidated. However, deliberately inducing crying for the sake of achieving awe is impermissible (ghair mashru'), and it is disliked (makrooh) if it does not result in the emission of two letters. But if it causes the emission of two or more letters, it invalidates the prayer. Inducing crying is disliked, similar to inducing laughter, lest two letters are emitted and the prayer becomes invalidated.