Which provision of the Hindu Marriage Act, 1955 defines 'sapinda relationship'?

Section 3(f) of the Hindu Marriage Act, 1955 defines 'sapinda relationship' as extending as far as the third generation (inclusive) in the line of ascent through the mother, and the fifth generation (inclusive) in the line of ascent through the father, the line being traced upwards in each case from the person concerned, who is to be counted as the first generation. Under Section 3 of the Act, Section 3(a) defines 'custom' and 'usage', Section 3(b) defines 'district court', and Section 3(g) defines 'degrees of prohibited relationship'.