Generate a digital illustration based on Galatians 4:22-23 - “For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman. But he who was of the bondwoman was born according to the flesh, and he of the freewoman through promise”. The scene incorporates middle-eastern biblical figures Abraham, his two sons, the bondwoman and the freewoman. The son from the bondwoman embodies tangible, realistic features indicating a birth 'according to the flesh', while the son from the freewoman emits an ethereal glow or other symbolic representation to signify his birth 'through promise'.