There is a saying in the English language that holds one bird in the hand to be worth two in the bush. The interesting part of the proverb comes with the comparison between actually having a certain quantity of the good, on the one hand, and having a greater quantity in view, on the other. The metaphor marked the distinction between that which is accessible and that which is inaccessible. In the metaphorical language characteristic of everyday wisdom, 'hand' stands here for actual possession, whereas ‘bush’ refers to present unavailability and potential, but uncertain, future possession. A difference in quantity of the good is here related to a difference in accessibility, and that the question of accessibility itself is confined to having and not now, or yet having.
what does "the question of accessibility" mean?
"Question" = Issue. "Accessibility" = The capability or possibility of obtaining the entity ("good"), but not actually possessing or obtaining it.