It cannot get any worse than this. On top of a mountain Abraham has toiled since dawn and the sun is now blazing over him.

While it was still dark he left his servants below in the valley, telling them that he and his son Isaac were going to worship up in the clear air. Abraham had scooped up a bundle of chopped wood. These were branches and kindling he had himself cut. He and Isaac had walked the narrow path. Abraham had said nothing. His eyes were like gledes, spat from a fire.

On a limestone platform Abraham built a neat pyre of wood with plenty of space between the crossed sticks, so that the wind would fan the flames quickly.

Yesterday a voice as intimate as his own had come to him, saying, ‘Behold, here I am. Take your son, your only son, into Moriah and make a burnt offering of him on a peak to which I will guide you.’

Now he stands with a flame in his left hand and a knife in the right hand. Isaac turns to him. ‘Father,’ he says. ‘Here is the wood and the fire but we have no lamb to offer.’

Abraham’s voice is heavy and cold as a bolt of iron. ‘God will provide a lamb for burning.’ He then moves to bind Isaac. The boy’s face is white as fleece. Abraham lays him on the pyre, as if he is putting him to bed. Isaac does not say a word as Abraham lifts his long, cold blade.

There is a glimmer across the face of the terrible sun and a figure, the likeness of a shining man, steps into the noon moment, saying ‘Abraham, here am I. Do not kill your son. For I know now that you revere God.’ I am the messenger of the Lord.

Abraham hears bleating and looks across the pyre to see a ram caught by its horns in a thicket. This he slays offered up instead of his son.

The shining figure comes again as they descend from the peak. He walks beside Abraham telling him that there is a new message. ‘Because you offered your only son, I will bless you and make your descendants as numerous as the stars in the sky and as the sand on the seashore.’

All this the messenger says and more. But Abraham is numb and cold, as if he has been stung, and it takes a good while for the news to sink in.