“I will be sanctified among the children of Israel.”
– Leviticus 22:32, JPS 1917 Tanach
Selfless behavior could be defined as being in tandem with the theme of mesiras nefesh – self-sacrifice. By way of explanation, mesiras nefesh may be viewed as an ongoing act, in the sense of subduing the yetzer hara (evil inclination), for the sake of sanctifying H’Shem’s name. The resultant reward is that we ourselves become sanctified, every time that we do not give in to our own character weaknesses. This is a challenge that appears in many circumstances on a daily basis; therefore, it is best to be on guard against temptation, by strengthening ourselves through constant vigilance.
To be selfless, in respect to mesiras nefesh on the level of morality, is to actively engage in diminishing our own will in favor of the ratzon (will) of the L-RD. When we negate ourselves, we renew ourselves for the sake of H’Shem who sanctifies us. This is a two way street of reciprocity; in other words, like two sides of the same coin. Whereof we are sanctified by H’Shem, through our own efforts to become holy; when we separate ourselves from unholiness, we are blessed with an equal measure of kedushah from the L-RD. By serving H’Shem, we bring kavod (glory) to Him.
“You are my servant, O Israel, in whom I will be glorified.”
– Isaiah 49:3
The Tree of Life 