Jamieson, Fausset and Brown on 2 Corinthians 5:2

2. For in this--Greek, "For also in this"; "herein" (2Co 8:10). Alford takes it, "in this" tabernacle. 2Co 5:4, which seems parallel, favors this. But the parallelism is sufficiently exact by making "in this we groan" refer generally to what was just said (2Co 5:1), namely, that we cannot obtain our "house in the heavens" except our "earthly tabernacle" be first dissolved by death.

we groan--(Ro 8:23) under the body's weaknesses now and liability to death.

earnestly desiring to be clothed upon--translate, "earnestly longing to have ourselves clothed upon," &c., namely, by being found alive at Christ's coming, and so to escape dissolution by death (2Co 5:1, 4), and to have our heavenly body put on over the earthly. The groans of the saints prove the existence of the longing desire for the heavenly glory, a desire which cannot be planted by God within us in vain, as doomed to disappointment.

our house--different Greek from that in 2Co 5:1; translate, "our habitation," "our domicile"; it has a more distinct reference to the inhabitant than the general term "house" (2Co 5:1) [Bengel].

from heaven--This domicile is "from heaven" in its origin, and is to be brought to us by the Lord at His coming again "from heaven" (1Th 4:16). Therefore this "habitation" or "domicile" is not heaven itself.