"And do not make your hand chained to your neck," Al-Hasan said: It means: Do not be [stingy and withholding], for then your likeness will be like him whose hand is chained to his neck. "Nor extend it completely," so that you spend [your wealth] on other than righteousness, "so that you become blamed," among the servants of God, unable to [accommodate] the people, "and regretful," meaning: that which was in your hand has departed.
Muhammad said: The "mahsūr" (regretful/exhausted) and the "hasīr" (worn out) is one who has reached the limit of fatigue and weariness. The meaning is: the act of giving exhausts you and leaves you incapacitated.