Midrasz do Samuela II 22:44

These are the accounts of the tabernacle (Exod. 38:21). Scripture states elsewhere: Thou hast also delivered Me from the contentions of My people (II Sam. 22:44), and it is written elsewhere: Thou hast delivered me from the contentions of the people (Ps. 18:44). The contentions of the people refers to the nations of the world, and the contentions of My people alludes to Israel. David said: Master of the Universe, the Israelites are a contentious lot; do You wish them to murmur against me amongst themselves? A proof of this is that after the Tabernacle was erected, though everything was done according to numbers and weights, as it is written: The whole by number and by weight; and all the weight was written at that time (Ezra 8:34), they became contentious, as is said: And the people spoke against God, and against Moses (Num. 21:15). Hence, it says: Thou mayest deliver me from the contentions of My people (II Sam. 22:44). This verse alludes to Moses. At the time he erected the Tabernacle, Moses said: I know that the Israelites are a troublesome lot. They speak against their brothers and their mothers, as it is said: Thou sittest and speakest against thy brother; thou slanderest thine own mother’s sons (Ps. 50:20). What is meant by Thou sittest and speakest against thy brother? R. Johanan said: You must not believe that one is permitted to speak against a brother born of one’s father, but not against a brother born of one’s mother, for if you should speak against your brother born of your father, you will eventually speak against your brother born of your mother, as it is said: Thou sittest and speakest against thine own brother; thou slanderest thine own mother’s sons.