O you who believe! Be afraid of Allah,
and be with those who are true (in word and deeds).
(Qur'an, At-Tawbah 9:119)
Lying is another disease of the heart. It does not have to be an outright falsehood for it to be considered a lie. It could be pretending to give something when there is no intention to give. Abdallah ibn Amir (r) said, "One day, the Messenger of Allah (s) came to my house when I was a child. I went to play and my mother called me saying, "O Abdallah, come so that I can give you something," The Prophet (s) asked, "What did you intend to give him?" She said that she wanted to give me some dates. He (s) said, "If you did not, then a lie would be written against you." (Abu Da'ud)
As parents we need to be careful that we do not commit this sort of lie - to pretend to give our children something to get them to do what we want then when they do it we don't give it to them. How many times have we seen parents holding a lolly in front of a young child and say, "Come here, I will give you this" but when the child comes the lolly is hidden away as the parent grabs the child? Imagine the child's feelings when s/he searches for the lolly but it is no where to be seen.
Children have a good memory for things that are promised to them. They do not forget so easily. For example, I promised to give my son a Kinder Surprise chocolate egg for doing something (I can't remember what it was) but when he did it I realised that I didn't have any Kinder Surprise left so I told him that the next time I go shopping I would get it for him. But, subhanallah, every time I went shopping I always forgot to buy it. Then one day he said to me, "Mum, you promised to give me a Kinder Surprise but you never did." May Allah forgive me. When he said that I felt like someone had gutted me. I cannot describe how bad I felt. I made a mental note to go shopping the next day to get the Kinder Surprise for him (and I finally did, alhamdulillah). Had I not finally given it to him, my son would have thought that I had lied to him and I know that would have lowered his respect and esteem for me.
This example was to illustrate that children do not forget any promises made to them. Although that incident happened weeks before, my son remembered. I had fully intended to give him what was promised to him but can you imagine what it would be like if I had not intended to give him what was promised? The result would have affected my relationship with my son and my relationship with Allah. For surely, Allah would have written me as a liar: Once, after the death of the Prophet (s), Abu Bakr (r) gave a khutbah. He said, "The Messenger of Allah stood in this very place in the first year and then he cried and he said, "Indeed lying leads to inequity and indeed inequity leads to the Fire. A man will lie until he is written as a liar with Allah." (Agreed Upon)
So take care to fulfill our promises.