In[42]:= {{2}, {3}} // MatrixForm

In[1]:= {{2}, {3}} // MatrixForm

In[2]:= ToExpression[InString[1], StandardForm, Defer] // DisplayForm

CellPrint@
Cell[Cases[NotebookRead@Cells[],
Cell[x_, _, _, CellLabel -> "In[42]:="] -> x][[1]], "Input"]

reprintInput[n_] := CellPrint @ Cell[
    BoxData[ToExpression@InString[n]],
    "Input"
]

$Line=41;
{{2}, {3}} //MatrixForm

reprintInput[42]