Introduction: In the book "The Making of the Awadh Culture", the author, Roshan Taqui, narrates that the dewan warned the maharaja not to double the land tax forthwith. Here are the reasons why:

1. Economic Implications:
The dewan had warned the maharaja about the economic implications of doubling the land tax. By doubling the land tax, the revenue generated from it would increase, but it would also lead to a decrease in the income of the farmers, who were the backbone of the economy. As a result, the farmers would become impoverished, and it would lead to an increase in the number of people migrating to other regions in search of work.

2. Social Implications:
The dewan also warned the maharaja about the social implications of doubling the land tax. By doubling the land tax, the farmers would be forced to pay more money to the government, which would lead to resentment among them. It would also lead to an increase in the number of farmers who were unable to pay their taxes, which would lead to their lands being confiscated by the government. This would lead to a rise in social unrest and rebellion.

3. Political Implications:
The dewan also warned the maharaja about the political implications of doubling the land tax. By doubling the land tax, the maharaja would be seen as a ruler who was insensitive to the needs of his subjects. This would lead to a loss of support from the people, and it would lead to a decline in the popularity of the maharaja. This would also lead to a decline in the political power of the maharaja.

Conclusion:
In conclusion, the dewan warned the maharaja not to double the land tax forthwith because of the economic, social, and political implications of such an action. The dewan was a wise and experienced advisor who understood the needs of the people and the impact of government policies on their lives. The maharaja would do well to listen to the dewan's advice and make decisions that were in the best interests of the people.