「當亞伯拉罕年老的時候，撒拉懷了孕；到神和亞伯拉罕約定的日期，就給亞伯拉罕生了一個兒子。」－創世記21:2
神的時間表都已經籌算好了，但那是人無法預先洞見的。
倘若亞伯拉罕還在哈蘭的時候，神事先告訴他必須等候三十年，才能得到應許的孩子－以撒，亞伯拉罕必定無法接受神這樣的安排。
因著愛，神必須向亞伯拉罕隱瞞這段漫無止境的年日；直到時日將近的幾個月前，才告訴他：「到了約定的日期，...撒拉必生一個兒子。」（創世記18:14）
神所定的日期最後終於來到了，喜樂終於溢滿了信心之父的家；在狂喜中，老夫婦忘卻了這段難熬等待的年歲。
在苦難中等待的聖徒們啊，提起你們的勇氣吧！你們所等待的這一位，是不會令你們失望的；祂必在所定的時候答應你們的求告，並且分秒不差。
不久，「你們的憂愁，要變為喜樂」。（約翰福音16:20）
神將要使你歡笑！就像黑夜遇到白晝，憂愁和哭泣將要在你面前落荒而逃。－選
"Sarah bare Abraham a son in his old age, at the set time of which God had spoken to him" (Gen. 21:2).The counsel of the Lord standeth forever, the thoughts of His heart to all generations" (Psalm 33:11). But we must be prepared to wait God's time. God has His set times. It is not for us to know them; indeed, we cannot know them; we must wait for them.
If God had told Abraham in Haran that he must wait for thirty years until he pressed the promised child to his bosom, his heart would have failed him. So, in gracious love, the length of the weary years was hidden, and only as they were nearly spent, and there were only a few more months to wait, God told him that "according to the time of life, Sarah shall have a son." (Gen. 18:14).
The set time came at last; and then the laughter that filled the patriarch's home made the aged pair forget the long and weary vigil.
Take heart, waiting one, thou waitest for One who cannot disappoint thee; and who will not be five minutes behind the appointed moment: ere long "your sorrow shall be turned into joy."
Ah, happy soul, when God makes thee laugh! Then sorrow and crying shall flee away forever, as darkness before the dawn. --Selected
