Nasso: B’nei Yisaschar: “Service as Burden”
The soul constantly longs to serve its Creator out of love, as to the Angels, “Mighty in strength that fulfill His word, hearkening unto the voice of His word (Psalms 103:20).” In serving God, the angels long for a reward; that they should be granted an additional way to serve God, for they long for Divine service, constantly.
“Service as burden (Numbers 4:47),” can be explained as service out of fear of God. Man does not receive pleasure from this toil; rather, he carries the yoke of service as a burden because of the dread of God.
“Service as gift (Numbers 18:6),” is service out of love. Man receives pleasure from toiling in this type of service.
This service is truly a gift from God, as it is written, “you shall see your world in your lifetime (Berachot 17a),” you shall receive the pleasures of Eden, the eternal world, in this world, in your lifetime. (Rabbi Zvi Elimelech of Dinov; B’nei Yisaschar, Nisan, Ma’amar 3, #9)