Hello, I have two questions regarding the halachos of making something הֶקְדֵשׁ (Consecration for the Temple Needs). 1. Can one have in mind for something to be הֶקְדֵשׁ or he actually has to speak it out? 2. Can one make something הֶקְדֵשׁ now nowadays? Thanks!
ב"ה Shalom According to the Rambam (מעשה הקרבנות יד:יב) Hekdesh applies also by thought. This is based upon the Gemara ( Shavuot (26B) and Yerushalmi Nazir 5:1) which derive from the Pasuk (שמות לה:כב) "all those generous at HEART" , that it includes dedications made at heart. The opinion of most Rishonim is that Hekdesh done in mind does not just require the person to donate the animal for a sacrifice as he thought, but it also sanctifies the animal. (See Rashi kiddushin 41 b) In regard to your second question, can someone make something Hekdesh in our time without a Bet Mikdash? The Gemara addresses this question (Yoma 66a) and says that one should not declare something Hekdesh in our time, since the object which becomes Hekdesh becomes irremediable. If someone, went ahead and declared something Hekdesh, the Gemara continues to specify different items and what is to be done with each item. The bottom line being that, whatever was declared Hekdesh finds its way to waste so that none benefit from it. This is also codified in the Rambam (הלכות ערכין ח:ח). All the best