출애굽기 20:6의 Musar

3) The third method of acquiring that status of doing מעשים טובים, is performance of the commandment when it involves various degrees of self sacrifice, מסירת נפש. The Mechilta explains this in connection with Exodus 20,6, where G–d promises reward for the next two thousand generations to people who have performed His commandments, whereas in Deut 7,9, the reward is promised for one thousand generations. The difference is due to whether the commandments have been performed out of love for G–d or out of fear of G–d. Isaac is reported to have replied to Ishmael who had boasted of his מסירת נפש when undergoing circumcision at the age of thirteen, a deed Isaac could not match since he had been only eight days old at his own circumcision. He told his half-brother Ishmael that he would offer up all his organs at the עקדה, thus proving even greater self-sacrifice.