Looking for a birthday gift

I am anticipating for the upcoming birthday party for my dad this coming weekend. We've planned the said occasion for months, and I'm happy that everything is all set. We are all excited because my dad will be surprise for he doesn't have an idea about the party. Four more days and we will be celebrating his 61st birthday! And also it's a double celebration since it will be a father's day as well. What a day to celebrate the special occasion!

Although the special occasion is only few days away, but I have yet to buy gifts. I am debating whether I should buy something or give dad's cash. That's a maybe option for now. I am thinking of giving him scopes for it is a good piece to have and perfect choice of a gift. But I don't know if he would like it. I might need to discuss that option to my sister first. My dad is hard to buy sometimes, so I need help or opinion when it comes to buying gifts especially just for him.