The word “came” leads us to ask where he had been. Was he not at his wife’s bedside when she passed away?
Some link this verse with the story of the Akedah in the previous chapter and say that when Sarah heard that Isaac had nearly lost his life the shock killed her.
Others (e.g. Rashi) suggest he had been looking after his flocks at Beer Sheva.
Ramban argues that since a Biblical wife had her own tent (Gen. 24:67), Abraham came from his tent to hers.
It may be that “came” reflects mere linguistic usage; it does not mean he physically came from anywhere but simply proceeded to mourn when she had died.
The question we ask is however not merely why he came but why he mourned first and wept for her afterwards. Surely human nature would go the other way!
But perhaps there are two reasons, not one, to cry when a person dies.
The first tears are the outpouring of emotion. The second are in a sense more intellectual.
“To mourn” is lispod, which has the sense of eulogising, giving a hesped.
What does a eulogy do? It describes, it assesses the person who has died. Mourning is not just feeling but thinking, reflecting, contemplating. The mind arouses the heart.
If the past saw many years of shared life when you thanked God for the person who has now gone, their death inevitably, tragically concentrates your thoughts. No wonder, like Abraham, you cannot help crying.
Judaism knows this, but it also promises that the Almighty will “make death pass into life eternal, and the Lord God will wipe away tears from off all faces” (Isaiah 25:8).