# How to fill a tensor with matrices one by one?

I have this tensor:

nn = 4;
tableToFill =
Table[x, {p, 1, nn}, {q, 1, nn}, {i, 1, nn}, {j, 1, nn}];


that I want to fill with a matrix one by one with a matrix that I get. say the first matrix would be in position 1,1 of the tensor so it would be the top left.

It would look something like this:

I started using a loop but it fills all my matrices with the same numbers.

Do[{tableToFill[[row, col]] = newMatrix
}, {row, 1, nn}, {col, 1, nn}]
MatrixForm[tableToFill]


Start by generating an array m of the appropriate dimensions. The four by four upper block is the 1,1 element of this, so setting m[[1,1]] to the desired 4 by 4 matrix does the trick.
m = ConstantArray[0, {4, 4, 4, 4}];