The scriptures often talk about attaining heaven. What was Sai's teaching about the nature of heaven and why we shouldn't necessarily desire it?

According to the teachings in Chapter 37, the conventional idea of heaven is questioned. It is described as merely a place for sensual enjoyment, from which one falls after their accumulated merit is exhausted. The text provocatively states there is no real difference in the quality of sensual pleasure, whether it's Indra in his heavenly garden or a donkey in a dung-heap. More importantly, we are asked what use a place, even heaven, is if it lacks the chanting of God's name or the presence of devotees. The earth-world is considered more profound because even a fleeting life dedicated to God can lead to a state of fearlessness.