OP, only you know (or can work out by asking them) if this is a gift being offered purely because they think that without it, you wouldn’t be able to afford a house, or if it’s being offered simply to make life a bi t easier for you.
Many parents will gift to their children, when it’s not a case of them not being able to live or buy a house without the gift. Many parents have some money and get enormous pleasure from seeing their children enjoy it and get the benefit of it whilst they are alive. Most people dont take the view that children must stand entirely on their own 2 feet and that a gift can’t be given or received unless the situation is dire and managing alone isn’t possible.
But OP, you are clearly worried about your parents’ attitude to the gift and to money. I think for your own peace of mind, you need to clarify the situation with them. It is irrelevant if other people’s parents would happily gift if you didn’t need the money for they would graciously accept regardless - this is about your family and their response to money.
So, go back to your family. Start by thanking them for their generous offer. Tell them you’d love to accept it. Tell them you want to check a couple of details and makes sure everyone is on the same page. Check first they can afford to give you the money and it has no strings attached. Then tell them that the money will make a big difference to you and that it will mean you can get a better interest rate and need to borrow a bit less. Tell them that without the gift you could stretch to buy with a worse interest rate and bigger loan, but you want them to know that you are able to stretch to do it yourselves. Again, thank them and just confirm that they are happy to gift the money. Then confirm the details of when and how the money will be available.
This last thu g about when the money will be available and in what form is important. On other threads, misunderstandings happen where parents say money will be gifted, but without clear timescales. Sometimes children think it will be soon but parents had no specific timescale and this causes problems later.
To be honest, communication is really important about stuff to do with money. People don’t like talking about it, make assumptions and misunderstandings develop. Always best to speak it all out and ensure you’re on the same page.
I’d hope that your parents confirm that they can afford to gift the money and do it with pleasure even if you can afford to buy without them. And that you can accept it happily and graciously and it gives all of you much pleasure. What a joy to be able to do this for your child and to receive like this as a child. Not everyone can afford to do it,but for those who can, it’s such a blessing.