How to say “Politically request verification” professionally

Level 1: To ensure we proceed with the utmost accuracy, could you please confirm the source or methodology used for these figures? Having this clarity will allow me to integrate the data seamlessly into the upcoming report.

Level 2: Before incorporating this into the final deliverable, I'd appreciate it if you could direct me to the validated source for these assumptions. My aim is to ensure our work reflects the most current and verified information available.

Level 3: Per our established quality assurance protocols and the need for a 'single source of truth,' kindly provide the definitive documentation or a link to the official repository for this data. This will ensure full compliance with our internal audit frameworks.

Level 4: I require verifiable data to proceed with this task effectively. Without a confirmed source for these details, I cannot guarantee the accuracy of the outcome, which could impact project timelines and validity.

Level 5: Prove it.

Level 1: To ensure we accurately reflect your requirements and deliver a solution that precisely meets your needs, could you provide the supporting documentation or a point of contact for these specifications? This will help us confirm our understanding.

Level 2: Thank you for these insights. Before we finalize our approach, it would be highly beneficial if you could share the underlying data or validation for these points. This helps us mitigate risks and ensure optimal outcomes for your project.

Level 3: We appreciate your input. As per Section 3.2 of our mutually agreed Statement of Work, all client-provided data requiring integration must be officially verified. Kindly forward the corresponding artifacts for our compliance review.

Level 4: Our project methodology requires verifiable inputs for all critical assumptions. Without clear documentation or a confirmed source for these details, we cannot proceed with this aspect of the project, which may impact timelines.

Level 5: We'll see about that.

Level 1: Thanks for sharing this! To ensure consistency across our collective work, could you share where you pulled these numbers from? Just want to make sure we're all referencing the same baseline.

Level 2: I appreciate you sending this over. For my records, and to maintain alignment, could you point me to the original documentation or data set you used? It helps with cross-referencing.

Level 3: Great contribution! Could you perhaps update the team's 'Single Source of Truth' document with the foundational metrics for this? It ensures everyone adheres to our shared data governance policies and avoids disparate inputs.

Level 4: I cannot integrate this information without a verified source. Please provide the origin of these details before I proceed, as inaccuracies will impact downstream processes.

Level 5: Is that even real?