B.G 2.13
देहिनोऽस्मिन्यथा देहे कौमारं यौवनं जरा। तथा देहान्तरप्राप्तिर्धीरस्तत्र न मुह्यति ॥ २-१३॥
The dweller of the body experiences childhood, youth and old age in the changing body. So also one gets another body (after death). It does not perturb the brave man.
Gīta Tātparya 2.13
Changing the body after death is no different compared to changing the body from youth to old-age. Using the word 'dehina' Krishna excludes his own body, as the body of God does not undergo change.
मम स्वकीयदेहान्तरप्राप्तिरपि नास्तीति दर्शयितुं देहिन इति विशेषणम्। भवदादीनां सा भविष्यतीत्यपि शोको न कर्तव्यः। देहस्येदानी- मप्यन्यथात्वदर्शनात् ॥ १३ ॥
Krishna used the adjective 'dehina', your body, to deny himself, the God, different bodies. Even if Arjuna and others get different bodies, they should not grieve. Because it does not differ from the body undergoing changes in current life when observed scientifically.