see: {lam skye ba dang rjes su mthun pa'i mthun rkyen 'khor lo bzhi} The 'four wheels of favorable conditions' conducive to the arising of the path [of liberation]
the wheel of four favorable things, the four favorable conditions. 1) {gnas pa} to be a god or human. 2) {brten pa} to follow a spiritual friend. 3) {smon pa} to aspire for {bdag nyid kyi blo chos} 4) {rgyu yod pa} to have merit from past lives