Financing advice needed

[Malik R.]

This may be a simple matter for many but with my limited knowledge, I can use advice from those in the know. If this is not the right forum for questions of this nature, please let me know and I'll move my question there.

My son owns a home out of state and wants to sell it and buy a replacement for about the same amount in state of his residence. He has found a property and is ready to make an offer but there are some challenges. The situation is:

His home is ready to be put in the market and will sell quickly however he does not have much money in his bank for a 20% down payment. The real estate agent is suggesting that having a pre-qualification letter from a lending institution will be helpful but I doubt such a letter can be obtained in his financial situation. I am willing to lend him full amount for cash purchase for the short term until his property sells.

What would be the best way to handle this and buy the new property without creating tax liabilities for any of us?