Not having had any significant religious training, biblical references tend to sail right by me. This line, for example, was, to me, about Hamlet identifying with a small insignificant creature, that when it goes, is particularly special. But no…. really, this is a line about God’s will being God’s will – that even something as small as which sparrow falls out of a man’s hand is guided by God’s hand. And also – the bible goes on about these sparrows that the “you” is more valuable than a whole bunch of sparrows. Which is kind of weird, I think. And explains why Christians tend to have this whole superiority over nature thing.
In any case – this line is such a direct reference to the bible, there is no question. All these years I was thinking that Shakespeare is just using images and poetic language in the middle of this bit – this sudden out-of-the-blue image – but no, it’s more like a supporting biblical reference to a case he’s making.