The acts of sacrifice, austerity and charity go well together. After completing the description of the qualities of sacrifice and austerity in the three modes of nature, Krishna now explains the same about charity.

A charity (dānaṁ) that is (yad) given (dīyate) out of duty (dātavyam iti) without expecting any favor back (anupakāriṇe), at the right place (deśe) and time (kāle ca), and to a worthy recipient (pātre ca) – that charity (tad dānaṁ) is considered to be (smṛtam) in the mode of goodness (sāttvikaṁ). (BG 17.20)

But (tu), that (tad) charity (dānaṁ), which is (yat) given (dīyate) grudgingly (parikliṣṭaṁ ca) for the sake of (ārthaṁ) receiving favor in return (pratyupakāra), or (vā) again (punaḥ) aiming (uddiśya) for some fruit (phalam) is considered to be (smṛtam) in the mode of passion (rājasaṁ). (BG 17.21)

A charity (dānam), which is (yad) given (dīyate) at an improper place and time (adeśa-kāle), and to an unworthy recipient (apātrebhyaś ca), without proper regard (asat-kṛtam) and without proper attention (avajñātaṁ) – that is (tat) said to be (udāhṛtam) in the mode of darkness (tāmasam). (BG 17.22)