2624. 'In his old age' means when the days had been completed for the human to be cast off. This becomes clear from the meaning of 'old age' as the state when He was to cast off the human and to put on the Divine, dealt with in 2198. For Abraham was at that time a hundred years old, a number which means a full and complete state of union, as will be clear from the explanation of verse 5.

2199. That 'well advanced in years' means that the time was at hand follows from what has now been stated. 'A day' in the Word, as also 'a year', and indeed 'time' in general, means state, as shown in 23, 487, 488, 493, 893. Thus: here 'advanced in years' means, in the internal sense, entering that state in which He was to cast off the human, and so means that the time was at hand.