For in this, that is, in this ruinous earthly tabernacle.
Observe here, The strength and vehemency of the saints' affection, we groan; the word signifies such a groaning as of a man that has a load or burden lying upon him, which makes him fetch his wind from his very bowels: as there are groans which proceed from sorrow, so there are groans which arise from desire and hope. Thus here, We groan, earnestly desiring.
Observe, 2. What is the subject which the apostle's groaning desires were carried out after; namely, to be clothed with a celestial body, instead of that clogging body of earthly corruption which here they carried about with them, earnestly desiring to be clothed upon, &c.
Learn thence, That such as do believe and wait for a blessed immortality, do groan for it, and earnestly desire it, because of the miseries and pressures by sin and sorrow in this present life; because they have already a taste of the happiness and glory of the life to come; and because the Holy Spirit doth excite and stir up these groaning desires in the hearts of believers; Rom_8:23 We also, that have the first fruits of the Spirit, do groan within ourselves.