You and Your in vv. 9-13 refer to Christ, as proven by the fact that vv. 11-12 of this psalm are quoted by Satan in Matt. 4:6 in reference to Christ. This indicates that in this psalm it is Christ who takes God as His habitation, His dwelling place. Thus, not only Moses took God as his dwelling place (90:1), but even the Lord Jesus, while He was on earth, took God the Father as His habitation. Moses, the lawgiver, and Christ, the grace-giver, were the same in taking God as their dwelling place, as their habitation. Thus, the saints (represented by Moses) and Christ are identified as one.
To be identified with Christ is to be identified with Him not only in His death, in His resurrection, and in His ascension but also in His taking God as His habitation. If we would be identified with Christ in His death, resurrection, and ascension, we need to abide in Christ (John 15:4), and to abide in Christ is not only to remain in Him but also to dwell in Him, taking Him as our everything.