They did not wait. They took a shortcut solution to God's promise which caused tragic consequences in the future of Abraham's descendants.
GOD'S PROMISE
Waiting on the Lord and focusing on His promise is dependent on your knowledge of Him. The more you know God, the more you can trust Him and wait upon Him. Without the knowledge of God's promises, it is hard to wait. Reading God's word will help you rest in the truth and certainty of His promises.
GOD'S WAY
Waiting on the Lord is a command. It is respectful submission to His authority (1Peter 2:18-19).
Running away from problems in your relationships, jobs, ministries, etc. will not solve it. You will only end up in a vicious pattern of taking the easy way out. Shortcut solutions will only cause more long term problems. Before taking any step, pray to seek God for wisdom to act in God's way.
GOD'S TIMING
We want the best, but we do not want to wait. Some of use move ahead of God while others are too slow, still asking for signs even when God's time has already arrived. To know God's timing, pray, listen and obey God's leading.
GODS BEST (Genesis 17:16-17)
After 25 years of waiting Abraham was 100 years old and Sarai was 90, she bore him a son, and they named him Isaac. God fulfilled His promise His way and in His time. Waiting on the Lord may be difficult or painful, but not waiting is harder in the long run. You will miss out on His best for your life.
Do you want God's best? Then, you must wait on Him. Focus on God's promises, follow His way and wait for His timing. As you seek and wait on the Lord, your heart will be transformed. Your affections will be transferred from the blessing to the One who blesses, from the gift to the Giver.
The greatest blessing in waiting is GOD Himself.