What is mentioned regarding
kissing the shaykh's hands and feet and falling down to kiss his feet while he is standing in addition to putting their foreheads against his hands falls under exceeding the proper limits in honoring a creature. This was not done with the Prophet (peace be upon him) or with the Rightly-Guided Caliphs. Moreover, these practices may be a means leading to major Shirk (associating others with Allah in His Divinity or worship). Prostrating before anyone apart from Allah is even a form of major Shirk.