Is spitting towards the Qiblah during prayer—while acknowledging its impermissibility—one of the acts that invalidate the prayer? And what is the criterion that makes a forbidden act also invalidate the prayer?

Spitting towards the Qibla during prayer is disliked (makrooh), and some scholars have deemed it forbidden (haram). It has not been reported that spitting towards theQibla invalidates the prayer unless it is continuous and excessive, in which case it would be considered an abundant action that invalidates the prayer.