A miscellaneous rule in Biblical grammar states that the pronoun for himself when used in a sentence functions adverbially to indicate that the activity of the sentence was done for personal reasons.

A good example of this occurs in Nu10-01:02 And HaShem spoke unto Moses, saying: Make for yourself two trumpets of silver; of beaten work shalt thou make them; and they shall be unto thee for the calling of the congregation, and for causing the camps to set forward. Rashi comments on the personal aspect of making the trumpets by providing three possible methods of personal aspect.
• Make the trumpets for yourself--only you can use them.
• Make the trumpets from your own funds
• The trumpets are used for your assemblies

Another example occurs at Ex18-27 which concludes the chapter describing how Jethro recognized the superiority of the Jewish God over other gods. The verse, translated with the above rule, states And Moses let his father-in-law depart; and he went for personal reasons into his own land. Rashi comments on the adverbial phrase: For personal reasons: He returned to found his own personal society/club of people who believe in a monotheistic God. The club/society he founded is referenced in Ju04-11. which states Now the Kenite society, who was of the descendants of Hobab the father-in-law of Moses, had separated himself from the Kenites, and pitched his tent near the terebinth in Zaanannim, which is by Kedesh.

An example from the parshah of Shlach Lechah occurs in Nu13-01:02 discussing God's allowance to Moses to send spies to scout out Israel before the Jewish conquest: The verses state And HaShem spoke unto Moses, saying: Send for yourself men, that they may spy out the land of Canaan, which I give unto the children of Israel; of every tribe of their fathers shall ye send a man, every one a prince among them.' Rashi explains: God told Moses Send for yourself - in other words, God allowed Moses to send spies to scout Israel before conquest,if he wanted to. That is, the spying was at Moses personal discretion.

A current example occurs at Dt13-17a discussing the plunder of the idolatrous city that was destroyed: And you shall gather all the plunder of it into the midst of the street and shall burn with fire the city, and all the plunder from it, for the Lord your God; and it shall be a heap forever; it shall not be built again. Rashi comments on the underlined adverbial phrase for the Lord thy God. It is gathered personally for God. Dedicate it to God. Here Rashi follows the general idea that an adverbial phrase beginning with for indicates personal use such as dedication.