1. Is the hadith: “A loan is treated as half of charity” authentic, and what does it mean? 2. Is the consultant sinful if he receives his salary from company (A) during his vacation and Eid holiday, despite his commitment to devising a work plan to compensate for his absence? And is he obligated to inform company (B) about company (A)’s shortcoming towards it, especially if (B) is uninterested in the project and has granted him absolute trust?

The narration you are asking about was not reported with this exact wording. Rather, it was reported with other wordings that convey similar meanings, indicating the virtue of lending, and that whoever lends to a Muslim twice, it is as if he has given the amount of the loan in charity once.

Regarding the questioner's situation with Company (A), he is considered a private employee who is entitled to the agreed-upon wage as long as he has made himself available for work during the contract period, even if he did not perform actual work. This is in accordance with the Hanafi school of thought. If Company (A) authorizes him to cease work during his travels, then the wage he receives is lawful and good for him. He is not obligated to inform Company (B) of his travel, because Company (A) is the real hirer. The questioner must be honest and diligent in his work, follow up with the company executing the projects, and report any shortcomings.