There lived an idolator in the past who made an idol out of stone and would worship it everyday. He would call it upon it by saying "Ya Sanam." For seventy years, he worshipped this idol. One day by mistake he uttered "Ya Samad" instead of Ya Sanam. Samad is a name of Allah which means The Self Sufficient Master. Allah Ta'ala immediately replied back to this idolator by saying "I am present oh My slave." The angels asked Allah why He replied to him since he didn't even call upon Him intentionally. Allah told the angels that for seventy years I have been waiting for this servant of mine to turn towards Me!
If a mother has only one child then how much would she love him? He would be the coolness of her eyes and the comfort of her heart. But if this son calls her saying "Mommy" more than four or five times, she would get irritated even though she loves him more than her ownself. On the other hand, when we call Allah once, He replies back to us 70 times by saying "Labbaik Ya Abdi (I am here oh My slave)." How unfortunate we are that we have not recognized our Allah who is so Kind, Merciful and Forgiving.
Source: Extracted from the lecture by Shaikh Tariq Jameel.