The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  7  0  0  0  7  7 28  0 21  7 42 14 42  0 35 28 14  7  7 28 21 35 14 21  7  7 21
 0  0  7  0  0 35 28 35  7 28 35 35  7  7  7 21 21 28  7  0 42 35 14 28  7 35 21 28
 0  0  0  7  0 35 21 21 35 35  7 42  0 14 42 14 21  7 21 21 14 35  0 28 21 21 35  7
 0  0  0  0  7 35 42  7 42  7  7  0 14  7  7 28 42 28  0 21 35 28 21 28  0 28  7  0

generates a code of length 28 over Z49 who´s minimum homogenous weight is 140.

Homogenous weight enumerator: w(x)=1x^0+594x^140+1248x^147+1908x^154+2658x^161+103872x^168+3444x^175+2724x^182+1074x^189+126x^196

The gray image is a code over GF(7) with n=196, k=6 and d=140.
This code was found by Heurico 1.16 in 5.16 seconds.